Tube and method of forming the same



Oct. 19, 1937. R. B. JOHNS 2,095,044

TUBE AND METHOD OF FORMING THE SAME Filed Sept. 25, 1936 Patented Oct. 19, 1937 TUBE AND METHOD OF FORMING THE SAME Roy B. Johns. Janesviile, Wia, assigno'r to The Parker Pen Company, Janelville, Wis.

Application September 25, 1936, Serial No. 102,483 1 Claim. (01. 154-2) pensive grades of fountain pens. The primary dimension as the thickness 01' the sheet the top 5 method used is old in the art and contemplates of the cemented sheet will be flush with the pe- 5 the wrapping of a thin celluloid or like plastic riphery of the core. A solvent is then applied to sheet about a preformed cylindrical tube of inexthe under side of the sheet and to the periphery pensive extruded stock. of the core and the sheet wound upon the said As explained above, the principal use to which core, the length of the sheet being such that the such stock is put is in the manufacture of founopposite edge from that cemented in the core 10 tain pens which, because of the public demand, overlaps that part of the edge lying within the said require the use of expensive mottled or other groove l2. The assembled piece is then permitdesigns containing pearl which is quite expensive. ted to dry and cure to an extent where the -In the manufacture of expensive pens, usually sheathing and core will be practically one piece solid pearl impregnated stock is used with the whereupon the wrapped tube is ground and in 15 center cored out to form caps and barrels, andin cross section the said tube becomes uniformly the medium priced pens sheets of expensive pearl spherical. impregnated Celluloid are wrapped on a mandrel, It is important to note that because of the either spirally or by the commonly known buttgrooved construction of the core and the method weld process, thus eliminating the waste due to of assembly of the sheet in the groove, upon wrap- 20 the coring of solid stock. In the low priced founping of the sheet upon .the said core and the overtain pen field, exterior appearance is still essential lapping of the two edges a thickness of pyroxylin and processes have been evolved whereby thin is presented at the jointure such that upon grindexpensive celluloid sheet stock is wrapped on an ing off the overlapping edge to form a spherical inexpensive core stock to form pen barrels and tube the wall thickness of the sheet at the jointure 25 caps. is greater than at any other place about the tube. The tubing formed by the last mentioned sheet Attention is called to Fig. 5 which discloses the wrapping process is unsatisfactory because the usual method of wrapping sheet stock about a seam formed by the jointure of the overlapping core. It is to be noted that in the process of edges of the sheathing stock is readily detectable. wrapping, a space I3 is left adjacent the lower edge 30 Also, after grinding the formed tube to make it of the wrapped sheet and upon grinding of the spherical in cross section, the weld at the joint assembled tube to make it spherical in cross secis so weakened as in many instances to cause the tion little or no stock is left at the jointure. It sheet to separate from the core. is true that in the wrapping process the stock may It is to these imperfections in the present methcave in at the joint to such an extent as to cause 3 ods of wrapping sheet stock upon a core that my the edge to adhere but the resulting ground piece invention is directed. shows a very definite ragged line running longi- Figure 1 is a plan view of a sheet of expensive tudinally of the tube and in time that portion of celluloid stock, approximately ten thousandths the sheathing that does not adhere directly to the thick, suspended over a tube of core material. core will cave' in and cause a very definite inden- 40 Fig. 2 is a cross sectional view disclosing the tation. edge of the sheet afilxed to the core material. By grooving the core and winding the sheet by Fig. 3 is a cross sectional viewdisclosing the my process the finished ground tubing discloses sheet wrapped on the core. little or no seam and thus eliminates the primary Fig. 4 is a cross sectional view of the wrapped objection to either the so-called spiral wrapped or 45 tubing after the grinding operation, and butt-welded stocks produced today.

Fig. 5 is a cross sectional view of a tube formed It is to be understood that the term Celluloid by the so-called butt-weld sheet wrapping procused in the foregoing specification and appended claim shall include any equivalent material. In the drawing, the numeral III will hereafter Having described my invention, what I claim 50 be used to indicate the sheathing sheet of exand desire to secure by Letters Patent, is: pensive Celluloid and the numeral Ii to indicate A process for wrapping sheet Celluloid on core the core on which the sheet is to be wrapped. In stock comprising the forming of a longitudinally my process a groove i2 is formed or milled in the extending seat in the core stock, the affixing of one core Ii, one plane of said groove being wider edge of the sheathing to the seat and wrapping 55 than the other to form a base on which one edge and cementing the sheathing about the core stock of the celluloid sheathing ill isaflixed. The depth with the opposite edge of said sheathing over of the groove tapers from ten thousandths at that lapping that edge aflixed to the seat. side against which the edge of the sheet is adapted to abut to the periphery of the tube and the edge ROY B. JOHNS.

My invention relates to a process of wrapping sheet Celluloid or other like plastic materials to form tubing stock such as is used in the less exof the sheet is cemented, through the medium of a solvent, into the said groove and due to the fact that the depth of the groove is the same 

